下面程序段的输出结果是？（ ）
def add_Run(L=None):
if L is None:
L = ['Lying']
else:
L.append('Run')
return L
add_Run()
print(add_Run())
print(add_Run(['Lying']))
'Lying']
['Run']
['Lying']
['Lying', 'Run']
[]